Supervisors info:
Κωνσταντίνος Σιμσερίδης, Επίκουρος καθηγητής, τμήμα φυσικής, Θεωρητική φυσική στερεάς κατάστασης, Εθνικό και Καποδιστριακό Πανεπιστήμιο Αθηνών.
Summary:
The charge transfer in aperiodic B-DNA polymers, including both possible base pairs (Adenine - Thymine, Guanine - Cytosine), is studied. The Tight Binding approach and in particular the wire model, where the carrier is located at a base pair (monomer), is used. Polymers made of N monomers are studied. Quasi-periodic (Fibonacci, Thue - Morse, Double Period, Rudin - Shapiro) and fractal (Cantor Dust, Asymmetric Cantor Set) monomer sequences are analyzed. The carrier is an electron or a hole, generated by reduction or oxidation, respectively. The on-site energies of the carrier at each base pair and the hopping parameters of the carrier from a base pair to its immediate neighboring base pairs are used. The carrier is placed at a monomer and its transfer along the polymer is studied. The calculated physical quantities are the eigenspectra of the HOMO and LUMO regimes, the corresponding densities of states, the HOMO-LUMO gap, the mean over time probabilities of finding the carrier at each monomer, the charge transfer frequency content (Fourier spectra, weighted mean frequency of charge oscillations at each monomer, total weighted mean frequency of the polymer) as well as the pure mean transfer rate from the first to the last monomer.
Keywords:
DNA, hopping integral, transfer integral, Tight Binding Model, aperiodic sequences, on-site energy.
